1. Water Pollution

2. Potential Test Questions:
1. List and discuss 6 categories of water pollutants.
2. Discuss how sewage is related to biological oxygen demand (BOD), dissolved oxygen, and eutrophication.
3. Discuss the problems associated with pesticide use. Use DDT as a specific example. (More in Ch 22)

3. Potential Test Questions:
Why were PCBs thought to be a ‘miracle chemical’? Why is this organic chemical an ‘environmental curse’.
Contrast point source pollution and non-point source pollution, giving examples of each.
6. Distinguish among primary, secondary, and tertiary treatments for wastewater.

4. Sources of Water Pollution

5. Water Pollution
Definition = physical, chemical, biological changes in water quality that adversely affect living organisms. (i.e., degradation)
Types:
Infectious Agents
Oxygen-Demanding Wastes
Inorganic Pollutants
Organic Chemicals
Sediment (Particulates)
Thermal Pollution

6. Infectious Agents
Infectious Agents = pathogenic organisms. Water-borne diseases from infectious agents include typhoid, cholera, bacterial and amoebic dysentery, polio, infectious hepatitis, guinea worm and schistosomiasis. Due to lack
of sanitation.
Analyze coliform bacteria (E. coli). Presume if coliform bacteria are present, infectious pathogens are also present.

8. Eutrophication
Eutrophication is the natural process by which waters (lakes, rivers etc) become excessively enriched with nutrients, typically nitrogen and phosphorus. It is one of the ways in which a water body (lake, rivers, and seas) transforms from a state where nutrients are scarce (oligotrophic), through a slightly richer phase (mesotrophic) to an enriched state (eutrophic).
Human activities often enhance the rate of change due to activities such as farming, forestry, road-building, industry and waste treatment that cause nutrients to enter watercourses. This nutrient enrichment often results in a population explosion of algae and other aquatic plants.

9. Oxygen-Demanding Wastes
Oxygen dissolved in water is indicator of water quality. 6 ppm O2 or more supports desirable aquatic life.
BOD (biochemical oxygen demand) measures the amount of dissolved oxygen consumed by aquatic microorganisms. Sewage, paper pulp, or food wastes can cause an Oxygen sag, where few fish survive.

10. Eutrophication
BOD and Eutrophication - rapid succession in a body of water because of an increase in biological productivity. (Oligotrophic lakes and rivers have clear water and low biological productivity).

11. Eutrophication - Solutions
Limit your fertilizer use and apply at appropriate times
Control runoff and soil erosion
Start a compost pile and recycle yard waste
Conserve water and energy
Plant trees and other deep root plants

12. Inorganic Pollutants
Heavy metals, like mercury, lead, tin, cadmium, selenium, and arsenic are caused by human activities.
Mother and Son
Minamata Bay, Japan

13. Inorganic Pollutants Metals:
Mercury poisoning from coal, incineration Causes: - damage to the nervous system
metal retardation
cerebral palsy
development delays
- kidney disorders
Lead poisoning from incineration, pipes, solder (previously in shot, gasoline)
Causes: - miscarriages
- hearing loss
- learning disabilities

14. Mad Hatter
Mercury (Hg), once used extensively in the hat making process, caused a brain illness in many hatters. Hg is still a major water pollutant around Danbury, Conn - 19th century “hat making capital of the world.”

15. Inorganic Pollutants Nonmetallic Salts:
Arsenic from mining or drainage of desert soils
Causes: - anemia
- cancer
- death.
Sodium Chloride: Salinization
Acids:
Sulfur and nitrogen compounds from coal.
Causes: - pH changes which affect species
- leaches aluminum

17. POPs
Persistent Organic Pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment.
The "dirty dozen" includes: PCBs, aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorbenzene, mirex, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and toxaphene.

18. Organic Pollutants Examples = Dioxin, PCB, DDT (Chlorinated)
Dioxin: stable; slow to degrade

19. Organic Pollutants - Dioxin
Generated from: Burning wood, coal, oil, household trash, and chlorine bleaching of pulp and paper
Accumulates in fat of animals  biomagnification
Causes: cancer
weakened immune response

20. Organic Pollutants - PCBs
PCB = non-flammable; not dissolved in water; high boiling points; does not conduct electricity well. So used for transformers and capacitors.

21. Organic Pollutants - PCBs
More than one billion pounds of PCBs have been made.
Accumulates in fat of animals  biomagnification
Causes: cancer
hormonal and reproductive disruptions
decrease cognitive abilities (dopamine)

22. PCBs & GE
Between 1947 and 1977, General Electric dumped an estimated 1.3 million pounds of PCBs into the Hudson River. In 1983, the EPA classified the 200-mile stretch of the Hudson River, from Hudson Falls to the Battery in New York City, as a Superfund site under the Superfund law. $460 million to dredge hot spots.

23. Organic Pollutants - DDT
DDT is an insecticide; stable and slow to degrade.
Paul Muller won the Nobel Prize in 1948 for developing DDT.
Benefits = Controlled spread of malaria; Provided crop protection

24. Organic Pollutants - DDT

25. Organic Pollutants - DDT
Problems with DDT: DDT is not metabolized very rapidly by animals; instead, it is deposited and stored in the fatty tissues  biomagnification

26. Organic Pollutants - DDT
Toxic to fish
Increased mortality in birds: calcium decreased in egg shells
Organic Pollutants - DDT

27. Organic Pollutants - DDT
Estrogen mimic in Vertebrates: feminizes males - lower sperm count; alters behavior
Human Health
decreased mental function
male infertility
cancer
Organic Pollutants - DDT

28. Organic Pollutants - DDT
Unintentional Pathways:

29. Organic Pollutants - DDT
Problems with DDT (and other pesticides)
Evolution of resistance
Non-target species and creation of new pests

30. Sediments Sediment from erosion and runoff: Fills lakes
Obstructs shipping channels
Clogs hydroelectric turbines
Purification more costly
Sediments

31. Thermal Thermal Pollution = an increase in temperature
Can cause: thermal shock
parasites and disease
greater vulnerability to toxic pollutants

32. Specific Sources of Ground Water Pollution
(rate of breakdown is extremely slow in ground water)
Industrial waste into aquifer recharge zone
Surface runoff into abandoned wells - industry, agriculture, home
Leaking underground storage tanks of gas stations
Leaking septic tank into recharge area.
Injection wells for secondary recovery.

33. Water Pollution Control
Point Source: discharge of pollutants from single point.
Factories, power plants, sewage treatment plants, oil wells.
Non-point Source: sources of water pollution that are scattered or diffuse, not having a specific location. Farm fields, golf courses, lawns, cities, roads, clearcut forests, mines
Water Pollution Control
Reduce the sources of water pollution

34. Water Pollution Control
Agriculture is the biggest source of water pollution.

35. Pollution From Agricultural Runoff

36. Legislation Enacted to Improve Water
Clean Water Act: to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. (1972/77/81/87)
greatly decreased the amount of point source pollution.
PCB’s, DDT, and Dioxin are no longer allowed as waste products into waters.
Superfund Program: remediation of toxic waste sites created in 1980/1984.
Safe Drinking Water Act: regulates water quality in commercial and municipal systems. (1974)

39. Improved water quality has been one of the biggest success stories of the environmental movement.

40. Improved Water Quality
Chesapeake Bay - America’s largest estuary.
reducing nutrient loading
banning phosphate detergents
restoring seagrass and wetlands.
upgrading wastewater treatment plants

41. Municipal Sewage Treatment
Primary treatment: physical separation of solids
Secondary treatment: aeration tank, biodegradation
Tertiary treatment: remove phosphates/nitrates lagoon/marsh or trickling filter.
Bioremediation: use of organisms to remove water pollutants

44. Septic Tanks and Drain Fields.
Domestic Sewage Treatment
Septic Tanks and Drain Fields.